An international fraud in which a gang allegedly made thousands of pounds downloading its own songs from online music stores with stolen credit cards has been cracked by the Metropolitan police and the FBI, the Met claimed yesterday.

The gang are alleged to have made several songs which they gave to an online US company, which then uploaded them to be sold on iTunes and Amazon.

Over five months they bought the songs thousands of times, spending around $750,000 (£468,750) on 1,500 stolen US and UK credit cards, according to the Met. The criminal network then also allegedly reaped the royalties from the tracks, pulling in an estimated $300,000, paid by the two sites, which were unaware of the fraud being committed against them.

Sixty officers from the Met's central e-crime unit today arrested seven men and three women in London, Birmingham, Kent and Wolverhampton.

They are being held at police stations in London and the Midlands on suspicion of conspiracy to commit fraud and money laundering.

Scotland Yard said the arrests were the result of a parallel investigation with the FBI that began in February.

"It was established that between September 2008 and January 2009 a UK criminal network provided music via an online US company who uploaded the tracks to Apple iTunes and Amazon.com for sale," it said. "This is a significant case for the e-crime unit, which was set up 12 months ago.

"The unit has been set up to provide a point of expertise and a national and international response to online crime. The nature of online crime means the unit are actively developing cross-border partnerships both with other international crime agencies and businesses."

Detective Chief Inspector Terry Wilson, of the e-crime unit, said: "This has been a complex investigation to establish what we believe to be an international conspiracy to defraud Apple and Amazon. This investigation, with its national and international dimension, exemplifies why we have set up this national response to e-crime.

"It shows the success that can be achieved through our close working relationship with the FBI.

"We are now making it more risky for criminals who seek to exploit the internet and commit e-crime across national borders. We are working hard through partnership with industry and law enforcement to combat e-crime and are committed to pursuing those responsible."

West Midlands police assisted Met detectives during the arrests, in which 60 UK officers took part.

The arrests included three men aged 19, 23, and 41, and one woman, 37, all from Wolverhampton; a woman, 22, from Dartford, Kent; a woman, 36, and two men, 34 and 40, from Birmingham; and two men, 22 and 46, from Peckham, south London.